This invention relates to a control system for a geared automatic transmission applicable for an automotive vehicle.
Hitherto a control system for an automatic transmission is disclosed in Japanese Patent Provisional Publication No. 3-194256 which teaches a technique for carrying out a shift by disengaging a disengaging-side friction engaging element and engaging an engaging-side friction engaging element. This technique is configured as follow: The engaging capacity of the disengaging-side engaging element is set at a certain value for establishing a slip condition, so that the engine speed is held at a value according to a gear ratio obtained after a downshift (hereinafter referred to as “synchronization control”). When this engine speed is reached, the disengaging-side engaging element is put into a disengaging state while the engaging capacity of the engaging-side engaging element is increased, thereby accomplishing a good downshift.